The chest muscles (pectorals) are the muscles which bring the arms together in front of the body. Ideally, a full chest muscle exercise should involve full movement of the arms from a position as far as possible in back of the body to a position straight out in front of the body with the hands together, while providing resistance to this movement throughout its entire range. Most devices at present available for exercising the chest muscles do not permit a fully effective and efficient chest exercise to be performed. Those which do are very elaborate and expensive.
One common chest muscle exercise is the barbell bench press. To perform it, the person lies on his back, usually on a narrow bench, and pushes a barbell upward from his chest to the full extension of his arms. The exercise is inefficient because of the limited arm movement permitted. The barbell can only be lowered until it touches the chest, preventing the arms from moving any further in the posterior direction. When the barbell is fully raised, the hands and therefore the arms cannot be brought together because a fixed grip must be maintained on the barbell.
The dumbell bench press is another common chest exercise. It permits the arms to be lowered farther than the barbell bench press does and permits the hands to be brought almost together when the arms are fully extended in front of the body. However, once the arms are extended over the chest, there is no resistance to bringing the hands together, since gravity provides no resistance to the horizontal movement.
The limitations of the barbell bench press and dumbell bench press can be largely overcome by devices in which weights are raised and lowered by means of cables which are passed over pulleys affixed to a wall or stationary object. In some of these devices, the operator pulls directly on the end of the cables by means of handgrips. In others, the cables are pulled by wheels which rotate as the operator moves his upper arms. All these devices are very elaborate and costly, and either require large amounts of floor space to operate or permanently occupy floor space.